The theory of Relativity!?

Question

I just want to know the part were.
If I were to go on a space ship which travels at the speed of light for a month and come back to earth, when I arrive back my younger brother will be older then me.

Now how does that work.

Answer 1

Special relativity is a theory of the structure of spacetime. It was introduced in Albert Einstein's 1905 paper called "On the Electrodynamics of Moving Bodies". Special relativity is based on two postulates which are contradictory in classical mechanics:

The laws of physics are the same for all observers in uniform motion relative to one another (Galileo's principle of relativity),
The speed of light in a vacuum is the same for all observers, regardless of their relative motion or of the motion of the source of the light.
The resultant theory has many surprising consequences. Some of these are:

Time dilation: Moving clocks tick slower than an observer's "stationary" clock.
Length contraction: Objects are observed to be shortened in the direction that they are moving with respect to the observer.
Relativity of simultaneity: two events that appear simultaneous to an observer A will not be simultaneous to an observer B if B is moving with respect to A.
Mass-energy equivalence: E = mc², energy and mass are equivalent and transmutable.
The defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics by the Lorentz transformations

space time

spacetime is any mathematical model that combines space and time into a single construct called the space-time continuum. Spacetime is usually interpreted with space being three-dimensional and time playing the role of the fourth dimension. According to Euclidean space perception, the universe has three dimensions of space, and one dimension of time. By combining space and time into a single manifold, physicists have significantly simplified a large amount of physical theory, as well as described in a more uniform way the workings of the universe at both the supergalactic and subatomic levels.
In classical mechanics, the use of spacetime over Euclidean space is optional, as time is independent of mechanical motion in three dimensions. In relativistic contexts, however, time cannot be separated from the three dimensions of space as it depends on an object's velocity relative to the speed of light.

The term spacetime has taken on a generalized meaning with the advent of higher-dimensional theories. How many dimensions are needed to describe the universe is still an open question. Speculative theories such as string theory predict 10 or 26 dimensions (With M-theory predicting 11 dimensions, 10 spatial and 1 temporal), but the existence of more than four dimensions would only appear to make a difference at the subatomic level.

Answer 2

First of all unless your brother is a twin and born AFTER you then what you say can not be. You are only leaving for a month so there can be no more than a month change in your relative ages and, unless your mother can have babies within a month of each other, you would have to be gone for at least nine months or so. But let us say you are gone for 10 years.

Since travel at the speed of light is impossible for a spaceship, we will assume that you are traveling very, very close to the speed of light. It is a fact that moving clocks run slow compared with a clock at rest meaning that time passes more slowly. Now as far as you are concerned time is moving along just fine. You will notice nothing different. But when you return to earth it might seem like a couple of days have gone by but really 10 years will have gone by. So your younger brother is now older than you. This is the classic time dilation. A coupe of sources to look at.

Answer 3

This is called "Time Dilation" i.e, a moving clock ticks more slowly than a clock at rest.
if t1 is the the time interval on a clock at rest relative to an observer=the proper time,
and t is the time interval on clock in motion relative to an observer then
t= t1/((1-(v^2/c^2)^.5)
where v=speed of relative motion and
c=speed of light.
so the interval between ticks on a moving clock is greater than that between a normal clock.
even ur biological clocks like ur heart rate is similar to the normal clock hence when ur moving all ur body functions slow down and you age more slowly.
and as you can see from the equation the closer you travel at the speed of light the more slowly you age.
you can get a better understanding if you go through the "Twin Paradox".

Answer 4

Here's another example that is easier to understand. Superman is leaving Krypton planet which can be seen from earth as a star. The planet was already destroyed when Superman was only halfway to Earth. His space shuttle was quicker and faster than the speed of light while traveling to earth. Due to the space shuttle faster than the speed of light, he saw his planet in the night sky when he landed on earth. He thought that his planet is still alive but the truth is, he only arrived on earth earlier than the light emitted by his planet. It's like what he is seeing is a past.